Most likely the power supply board needs to be replaced. One or more of the capacitors is probably going bad.
If you don't know what you're doing, DON'T OPEN THE TV UP TO FIX IT, THERE ARE HAZARDOUS VOLTAGES ON THE POWER SUPPLY BOARD, EVEN WEEKS AFTER THE TV IS UNPLUGGED! The capacitors in particular have the high voltage.
If you don't know how to do it yourself, find some local Electronic repair shops, get quotes, try to find reviews on the shops.
Most people answering questions here don't even mention the high voltage on even modern TV's. Since you're an EE you know what's going on. It could just be a cap or two, but if the top of the cap isn't rounded, you may not find it. That power supply is less than $16 on ebay, $9 savings vs shopjimmy. At that price, it's not worth the hassle of replacing a cap if another one might go bad soon.Most people answering questions here don't even mention the high voltage on even modern TV's. Since you're an EE you know what's going on. It could just be a cap or two, but if the top of the cap isn't rounded, you may not find it. That power supply is less than $16 on ebay, $9 savings vs shopjimmy. At that price, it's not worth the hassle of replacing a cap if another one might go bad soon.
Answers & Comments
Most likely the power supply board needs to be replaced. One or more of the capacitors is probably going bad.
If you don't know what you're doing, DON'T OPEN THE TV UP TO FIX IT, THERE ARE HAZARDOUS VOLTAGES ON THE POWER SUPPLY BOARD, EVEN WEEKS AFTER THE TV IS UNPLUGGED!
The capacitors in particular have the high voltage.
If you don't know how to do it yourself, find some local Electronic repair shops, get quotes, try to find reviews on the shops.
Most people answering questions here don't even mention the high voltage on even modern TV's. Since you're an EE you know what's going on. It could just be a cap or two, but if the top of the cap isn't rounded, you may not find it. That power supply is less than $16 on ebay, $9 savings vs shopjimmy. At that price, it's not worth the hassle of replacing a cap if another one might go bad soon.